Data through August 31, 2013. Data Source: National Water and Climate Center
Combined water storage in the 15 New Mexico reservoirs reported here was 15.9 percent of capacity—a combined decline of 0.6 percent—and only 36.3 percent of average as of August 31 (Figure 7). New Mexico total reservoir storage decreased by 54,000 acre-feet in the last month, primarily as a result of decreases in Navajo and Heron reservoirs in northern New Mexico and Caballo Reservoir on the Rio Grande. Storage in several New Mexico reservoirs increased during the last month due to much needed summer monsoon precipitation. However, Elephant Butte Reservoir is still at an exceedingly low 4.1 percent of capacity. These reservoir levels reflect the effect of two consecutive years of extremely low snowpack in the mountain ranges in northern New Mexico and southern Colorado from which most of the water originates. Based on long-term drying trends, there are slightly enhanced probabilities that precipitation will be below average (see Precipitation Outlook). A third consecutive dry winter would further strain water supplies; this summer irrigators drawing water from Elephant Butte Reservoir received only 3 inches of water per acre. When the reservoir is flush, farmers receive 36 inches per acre.
The map gives a representation of current storage for reservoirs in New Mexico. Reservoir locations are numbered within the blue circles on the map, corresponding to the reservoirs listed in the table. The cup next to each reservoir shows the current storage (blue fill) as a percent of total capacity. Note that while the size of each cup varies with the size of the reservoir, these are representational and not to scale. Each cup also represents last year’s storage (dotted line) and the 1971–2000 reservoir average (red line).
The table details more exactly the current capacity (listed as a percent of maximum storage). Current and maximum storage are given in thousands of acre-feet for each reservoir. One acre-foot is the volume of water sufficient to cover an acre of land to a depth of 1 foot (approximately 325,851 gallons). On average, 1 acre-foot of water is enough to meet the demands of 4 people for a year. The last column of the table list an increase or decrease in storage since last month. A line indicates no change.
These data are based on reservoir reports updated monthly by the National Water and Climate Center of the U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS).